Nestable and stackable trays of single piece construction are known in the art. An example of such a tray is shown in the Bockenstette U.S. Pat. No. 3,392,875. The Bockenstette patent shows a nestable and stackable tray for bakery goods having posts spaced along the side walls which are shorter than the end walls to prevent the goods from sliding out of the tray while permitting inspection of them. Another Bockenstette U.S. Pat. No. 3,819,044 shows a tray of one piece construction having inner and outer parallel top stacking rails as well as inner and outer parallel bottom stacking rails. This later Bockenstette patent also features 90 degree nesting and stacking.
The Herolzer U.S. Pat. No. 3,780,905 shows a stackable nestable bakery tray with improved upper and lower stacking rails. The bottom stacking rail has floor engaging structures on opposite sides providing for a recess of a size able to receive a hand truck or the like. The Rehrig U.S. Pat. No. 3,675,815 shows a bakery tray which is molded from a single homogeneous mass of thermoplastic material. The end walls and side walls include means facilitating filling of the tray with packages of bakery products. The Thurman U.S. Pat. No. 4,106,624 shows a tray structure which is designed for nesting and stacking. Top, middle, and bottom rib and rail structures cooperate with the trays walls to prevent end-to-end as well side-to-side movement of the upper tray relative to the lower tray when the trays are in stacked, as well as in nested, relationship with one another. The Stahl U.S. Pat. Nos. 4,093,070 and 4,093,071, both show bakery trays of a single piece molded construction, and both are stackable and nestable type trays.